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Posting to multiply related tables Django

I would like to create my own endpoint for POST request to two related tables. I have two tables User and Userattribute.
models.py
class User(models.Model):
email = models.CharField(unique=True, max_length=180)
roles = models.JSONField(default=dict)
password = models.CharField(max_length=255, blank=True, null=True)
name = models.CharField(max_length=255, blank=True, null=True)
firebase_id = models.CharField(max_length=255, blank=True, null=True)
created_at = models.DateTimeField(default=now)
progress_sub_step = models.IntegerField(blank=True, null=True)
step_available_date = models.DateTimeField(blank=True, null=True)
progress_step = models.IntegerField(blank=True, null=True)
active = models.IntegerField(default=1)
last_login_at = models.DateTimeField(blank=True, null=True)
class Meta:
managed = False
db_table = 'user'
class Userattribute(models.Model):
user = models.OneToOneField(User, on_delete=models.CASCADE, primary_key=True, related_name = 'attribute')
attribute = models.ForeignKey(Attribute, on_delete=models.CASCADE)
The table Userattribute contains the field user which is OnetoOne to Id primary key from User table.
I tried to implement POST to two tables in serializers.py In the commented section there is a create definition which works perfectly for me. However, I wouldlike to move it to views.py as register_in_course endpoint
serializers.py
class FilmSerializer(serializers.ModelSerializer):
class Meta:
model = Film
fields = ['tytul', 'opis', 'po_premierze']
class UserattributeSerializer(serializers.ModelSerializer):
class Meta:
model = Userattribute
fields = ['user', 'attribute']
class UASerializer(serializers.ModelSerializer):
class Meta:
model = Userattribute
fields = ['attribute']
class UserSerializer(serializers.ModelSerializer):
attribute = UASerializer(many = False)
class Meta:
model = User
fields = ['email', 'name', 'firebase_id', 'attribute']
# This is what workks perfectly for me, and I want to move it to views.py
# VVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV
# def create(self, validated_data):
# attribute_data = validated_data.pop('attribute')
# user = User.objects.create(**validated_data)
# Userattribute.objects.create(user=user, **attribute_data)
# return user
Current views.py:
class UserViewSet(viewsets.ModelViewSet):
queryset = User.objects.all()
serializer_class = UserSerializer
#action(detail = False, methods = ['post'])
def register_in_course(self, request, **kwargs):
data = self.get_object()
user = User.objects.create(email=request.data['email'],
name=request.data['name'],
firebase_id=request.data['firebase_id'])
user_id = User.objects.filter(firebase_id = request.data['firebase_id'])['id']
attribute = Userattribute.objects.create(user = user_id, attribute = request.data['attribute']['attribute'])
user = user.attribute.add(attribute)
serializer = UserSerializer(user, many = false)
return Response(serializer.data)
Using endpoint register_in_course to POST I get following error:
Expected view UserViewSet to be called with a URL keyword argument named "pk". Fix your URL conf, or set the .lookup_field attribute on the view correctly.
urls.py
from django.urls import include, path
from django.conf.urls import url
from rest_framework import routers
from api import views
router = routers.DefaultRouter()
router.register(r'users', views.UserViewSet)
router.register(r'userattribute', views.UserattributeViewSet)
urlpatterns = [
url('', include(router.urls))
]

i removed one line user_id variable and changed attribute variable. please check, maybe it should solve your problem, because you have already have Assigned variable as a User object..
class UserViewSet(viewsets.ModelViewSet):
queryset = User.objects.all()
serializer_class = UserSerializer
#action(detail = False, methods = ['post'])
def register_in_course(self, request, **kwargs):
data = self.get_object()
user = User.objects.create(email=request.data['email'],
name=request.data['name'],
firebase_id=request.data['firebase_id'])
attribute = Userattribute.objects.create(user = user, attribute = request.data['attribute']['attribute']) # changed this line
user = user.attribute.add(attribute)
serializer = UserSerializer(user, many = false)
return Response(serializer.data)

This issue is caused by calling get_object in a view that is defined with detail=False:
#action(detail = False, methods = ['post'])
def register_in_course(self, request, **kwargs):
data = self.get_object() # The problem is caused by this line
It seems you don't need this data, as you are using request.data.
So you can define your view like this:
#action(detail = False, methods = ['post'])
def register_in_course(self, request, **kwargs):
user = User.objects.create(
email=request.data['email'],
name=request.data['name'],
firebase_id=request.data['firebase_id']
)
Userattribute.objects.create(
user=user,
attribute = request.data.get('attribute', {}).get('attribute', {})
)
return Response(UserSerializer(user).data)

drf serializer data not showing all fields data properly

id field and name field not showing in result.
in models.py:
class Group(models.Model):
id = models.AutoField(primary_key=True)
name = models.CharField(max_length=50)
admin = models.ForeignKey(User, on_delete=models.CASCADE)
member = models.ManyToManyField(User, related_name='groups_user')
def __str__(self):
return self.name
in serializers.py:
class SimpleUserSerializer(serializers.ModelSerializer):
class Meta:
model = User
fields = ('id','first_name', 'last_name')
class GroupSerializer(serializers.Serializer):
admin = SimpleUserSerializer()
class Meta:
model = Group
fields = ('id','name','admin')
views.py:
#api_view(['GET'])
#permission_classes((IsAuthenticated,))
def getSomeGroup(request):
allGroup = Group.objects.all().count()
randomGroupId = random.sample(range(allGroup), 3)
randomGroup = Group.objects.filter(id__in=randomGroupId)
serializer = GroupSerializer(randomGroup, many=True)
#print(serializer)
return Response(serializer.data)
the result comes like this:
[{"admin":{"id":1,"first_name":"asif","last_name":""}},{"admin":{"id":3,"first_name":"Test2","last_name":"lastname"}},{"admin":{"id":3,"first_name":"Test2","last_name":"lastname"}}]
why id and name field not showing?

class SimpleUserSerializer(serializers.ModelSerializer):
class Meta:
model = User
fields = '__all__'
First try to access all admin
#api_view(['GET'])
#permission_classes(IsAuthenticated)
def getSomeGroup(request):
randomGroup = Group.objects.all()
serializer = GroupSerializer(randomGroup, many=True)
return Response(serializer.data)
If that works there may be issue in your these two line
The Issue may be in these two lines
allGroup = Group.objects.all().count()
randomGroupId = random.sample(range(allGroup), 3)

Modify serializers.py:
class GroupSerializer(serializers.ModelSerializer):

Django rest framework, update object after creation

I have a DRF API that takes in the following model:
class Points(models.Model):
mission_name = models.CharField(name='MissionName',
unique=True,
max_length=255,
blank=False,
help_text="Enter the mission's name"
)
# Some irrlevant feid
url = models.URLField(help_text='Leave Empty!', default=" ")
date_added = models.DateTimeField(default=timezone.now)
class Meta:
get_latest_by = 'date_added'
And it's serializer:
from rest_framework.serializers import HyperlinkedModelSerializer
from .models import Points
class PointsSerializer(HyperlinkedModelSerializer):
class Meta:
model = Points
fields = (
'id', 'MissionName', 'GDT1Latitude', 'GDT1Longitude',
'UavLatitude', 'UavLongitude', 'UavElevation', 'Area',
'url', 'date_added'
)
And the view:
class PointsViewSet(ModelViewSet):
# Return all order by id, reversed.
queryset = Points.objects.all().order_by('-id')
serializer_class = PointsSerializer
data = queryset[0]
serialized_data = PointsSerializer(data, many=False)
points = list(serialized_data.data.values())
def retrieve(self, request, *args, **kwargs):
print(self.data)
mission_name = self.points[1]
assign_gdt = GeoPoint(lat=self.points[2], long=self.points[3])
gdt1 = [assign_gdt.get_lat(), assign_gdt.get_long()]
assign_uav = GeoPoint(lat=self.points[4], long=self.points[5], elevation=self.points[6])
uav = [assign_uav.get_lat(), assign_uav.get_long(), assign_uav.get_elevation()]
area_name = f"'{self.points[-2]}'"
main = MainApp.run(gdt1=gdt1, uav=uav, mission_name=mission_name, area=area_name)
print('file created')
return render(request, main)
I want to update the URL field of the file to contain a constant pattern and format in the end the mission_name field.
object.url = f'127.0.0.1/twosecondgdt/{mission_name}'
How can that be achieved and where should I store such code, the views.py or serializers.py?

There are several ways this could be achieved based on your requirements.
If you want to set the url upon creation even if it is not through the api, you can do it in the save method of the model itself:
class Points(models.Model):
# fields here
def save(self, **args, **kwargs):
if not self.url.strip():
# You may want to store the value of `127...` in an environment variable
self.url = f"127.0.0.1/twosecondgdt/{self.mission_name}"
super().save(*args, **kwargs)
If you want to set it through the view/serializer, you can set it in the create method of your serializer:
class PointsSerializer(HyperlinkedModelSerializer):
def create(self, validated_data):
mission_name = validated_data["mission_name"]
validated_data["url"] = f"127.0.0.1/twosecondgdt/{mission_name}"
return super().create(validated_data)
You can also override some methods in your viewset like perform_create or create

AttributeError with Django Rest nested serializer

I'm following the Django Rest documentation for writing nested serializer but it is giving me attribute error.
Here are my models:
class Objects(TimeStampModel):
projects = models.ForeignKey(Projects,related_name='proj_obj',on_delete=models.CASCADE)
object_name = models.CharField(max_length=50)
object_description = models.TextField()
object_main_table = models.CharField(max_length=50)
object_primary_key = models.CharField(max_length=50)
object_age_field = models.CharField(max_length=50)
date_format = models.CharField(max_length=50)
def __str__(self):
return self.object_name
class ObjectDefinition(TimeStampModel):
ATTRIBUTE = 'Attribute'
RELATION = 'Relation'
TYPE_CHOICES = (
(ATTRIBUTE, 'Attribute'),
(RELATION, 'Relation'),
)
obj = models.ForeignKey(Objects,related_name='obj_def',on_delete=models.CASCADE)
from_table = models.CharField(max_length=50)
from_table_field = models.CharField(max_length=50)
to_table = models.CharField(max_length=50)
to_table_field = models.CharField(max_length=50)
relation_type = models.CharField(max_length=50,choices=TYPE_CHOICES)
relation_sequence = models.CharField(max_length=50)
value_field = models.CharField(max_length=50, blank=True, null=True)
Here is my serializers.py snippet:
class ObjectDefinitionSerializer(serializers.ModelSerializer):
class Meta:
model = ObjectDefinition
fields = ('from_table','from_table_field','to_table','to_table_field','relation_type','value_field')
class ObjectSerializer(serializers.ModelSerializer):
definition = ObjectDefinitionSerializer(many=True)
object_description = serializers.CharField(required=False, allow_null=True, allow_blank=True
)
class Meta:
model = Objects
fields = ('projects','object_name','object_description','object_main_table','object_primary_key','object_age_field','date_format','definition')
def validate(self, data, *args, **kwargs):
date_format = data.get('date_format')
if date_format not in ['YYYYMMDD', 'DDMMYYYY']:
msg = ('Date format is incorrect')
raise serializers.ValidationError({'error_msg': msg})
return super(ObjectSerializer, self).validate(data, *args, **kwargs)
def create(self, validated_data):
definition_data = validated_data.pop('definition')
obj = Objects.objects.create(**validated_data)
for data in definition_data:
ObjectDefinition.objects.create(obj=obj, **data)
return obj
My views.py:
class CreateObject(CreateAPIView):
permission_classes = (IsAuthenticated,)
serializer_class = ObjectSerializer
After hitting POST, objects.create works fine for both the models but at return obj, it throws me this error:
Exception Value:
Got AttributeError when attempting to get a value for field definition on serializer ObjectSerializer.
The serializer field might be named incorrectly and not match any attribute or key on the Objects instance.
Original exception text was: 'Objects' object has no attribute 'definition'.
What am I missing?

The ObjectDefinition.obj's related_name is obj_def which doesn't match your serializer.
You can fix that by providing the source argument:
definition = ObjectDefinitionSerializer(source='obj_def', many=True)

JSONField serializes as json for POST, but string for GET

There is likely a very simple problem with my code, but I've been slamming my head against this problem for a couple days and can't make any headway.
Important Packages:
Django==1.11.3
django-cors-headers==2.1.0
djangorestframework==3.7.0
drf-nested-routers==0.90.0
psycopg2==2.7.3
pycparser==2.18
Here is what is happening:
I create a model via an AJAX call
My server correctly serializes the brainstorm_data field as a json object.
Now I navigate my user to the next page and fetch the current model
For some reason, brainstorm_data is now be returned as a string. Anytime I call a GET request on this resource I always get a string representation of the JSON object.
Here is the code associated:
models.py
from django.contrib.postgres.fields import JSONField
class Adventure(TimeStampedModel,
models.Model):
name = models.CharField(max_length=200)
user = models.ForeignKey(User)
world = models.ForeignKey(World)
theme = models.ForeignKey(Theme, default=1)
brainstorm_data = JSONField()
image_src = models.CharField(max_length=400, null=True, blank=True)
sentence_summary = models.TextField(null=True, blank=True)
paragraph_summary = models.TextField(null=True, blank=True)
page_summary = models.TextField(null=True, blank=True)
outline_complete = models.BooleanField(default=False)
brainstorm_complete = models.BooleanField(default=False)
private = models.BooleanField(default=False)
def __str__(self):
return self.name
views.py
class MyAdventuresViewSet(viewsets.ModelViewSet):
queryset = Adventure.objects.all()
serializer_class = AdventureSerializer
permission_classes = (permissions.IsAuthenticated,)
def get_queryset(self):
return Adventure.objects.filter(user=self.request.user)
def create(self, request, *args, **kwargs):
user = self.request.user
world = World.objects.filter(user=user).first()
if not world:
world = World.objects.create(name='My World', user=user,
description="This is a default world we created for your adventures",
image_src=static('worlds/images/world_placeholder.png'))
data = request.data.copy()
data['user'] = user.pk
data['world'] = world.pk
data['theme'] = 1 # default theme
data['brainstorm_data'] = default_brainstorm
serializer = self.get_serializer(data=data)
serializer.is_valid(raise_exception=True)
adventure = serializer.save()
Storyboard.objects.create(adventure=adventure, raw=default_storyboard['raw'], html=default_storyboard['html'])
return JsonResponse(serializer.data)
#detail_route(methods=['post'])
def complete_outline(self, request, pk):
adventure = Adventure.objects.get(pk=self.kwargs['pk'])
complete_adventure_outline(adventure)
serializer = self.get_serializer(data=adventure)
serializer.is_valid(raise_exception=True)
return JsonResponse(serializer.data, status=200)
#detail_route(methods=['post'])
def genres(self, request, pk):
genre_names = request.data
genre_models = Genre.objects.filter(name__in=genre_names)
adventure = self.get_object()
adventure.genre_set.set(genre_models)
adventure.save()
serializer = AdventureSerializer(adventure)
return JsonResponse(serializer.data)
serializers.py
class AdventureSerializer(serializers.ModelSerializer):
genre_set = serializers.StringRelatedField(many=True, read_only=True)
character_set = serializers.PrimaryKeyRelatedField(many=True, read_only=True)
location_set = serializers.PrimaryKeyRelatedField(many=True, read_only=True)
storyboard = serializers.PrimaryKeyRelatedField(read_only=True)
theme = serializers.PrimaryKeyRelatedField(queryset=Theme.objects.all())
class Meta:
model = Adventure
fields = '__all__'
mixins
# this is a dictionary used to default brainstorm data each time an adventure is created
default_brainstorm = {
"nodes": [...],
"edges": [...]
}

You can override the to_internal_value and to_representation in a new serializer field to handle the return data for JSON field.
class JSONSerializerField(serializers.Field):
"""Serializer for JSONField -- required to make field writable"""
def to_internal_value(self, data):
return data
def to_representation(self, value):
return value
And in turn, you would use this Field in a serializer:
class SomeSerializer(serializers.ModelSerializer):
json_field = JSONSerializerField()
class Meta:
model = SomeModelClass
fields = ('json_field', )
This should solve your problem :)

When I originally created the columns I did it with a different json field package. The base DB columns was actually text instead of json or jsonb. Creating new columns (django json fields), migrating the data, and then shifting the data back got my database back in a consistent order.